Display device

ABSTRACT

A display device includes a substrate, a first insulating layer disposed on the substrate, a through portion passing through the substrate and the first insulating layer, a display unit disposed on the first insulating layer and including a plurality of pixels surrounding at least a portion of the through portion, and a dummy pixel unit. Each pixel includes a light-emitting element including a pixel electrode and an opposite electrode facing each other, and an emission layer disposed between the pixel electrode and the opposite electrode. The dummy pixel unit includes a plurality of dummy pixels disposed between the through portion and the display unit, and including a metal pattern including a same material as the pixel electrode. The dummy pixels are disposed adjacent to the display unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/376,608 filed Apr. 5, 2019, which claimspriority under 35 U.S.C. § 119 to Korean Patent Application No.10-2018-0078935, filed on Jul. 6, 2018 in the Korean IntellectualProperty Office, the disclosures of which are incorporated by referenceherein in their entirety.

TECHNICAL FIELD

Exemplary embodiments relate to a display device, and more particularly,to a display device that provides different display area shapes andimproves display quality.

DISCUSSION OF THE RELATED ART

As display devices become thinner and lighter, their use cases haveexpanded. For example, display devices having various shapes are beingused for devices such as monitors, mobile phones, clocks, etc. Displayquality may deteriorate as a result of implementing certain changes whendesigning a display device to have a particular shape.

SUMMARY

Exemplary embodiments include a display device that diversifies a shapeof a display area and simultaneously improves display quality.

According to an exemplary embodiment, a display device includes asubstrate, a first insulating layer disposed on the substrate, a throughportion passing through the substrate and the first insulating layer, adisplay unit disposed on the first insulating layer and including aplurality of pixels surrounding at least a portion of the throughportion, and a dummy pixel unit. Each pixel includes a light-emittingelement including a pixel electrode and an opposite electrode facingeach other, and an emission layer disposed between the pixel electrodeand the opposite electrode. The dummy pixel unit includes a plurality ofdummy pixels disposed between the through portion and the display unit,and including a metal pattern including a same material as the pixelelectrode. The dummy pixels are disposed adjacent to the display unit

In an exemplary embodiment, the dummy pixels of the dummy pixel unit aredisposed successive with the pixels of the display unit.

In an exemplary embodiment, the display device further includes a firstpixel circuit and a second pixel circuit. Each of the first pixelcircuit and the second pixel circuit includes a thin film transistordisposed on the substrate. A first pixel from among the plurality ofpixels is electrically connected to the first pixel circuit, and a firstdummy pixel from among the plurality of dummy pixels is electricallyinsulated from the second pixel circuit.

In an exemplary embodiment, the display device further includes a vialayer covering the first pixel circuit and the second pixel circuit. Thevia layer planarizes a top surface of the via layer, and includes acontact hole that electrically connects the first pixel to the firstpixel circuit. The contact hole is not disposed between the second pixelcircuit and the metal pattern.

In an exemplary embodiment, the pixel electrode is electricallyconnected to the thin film transistor of the first pixel circuit, andthe metal pattern is electrically insulated from the thin filmtransistor of the second pixel circuit.

In an exemplary embodiment, the display device further includes a secondinsulating layer covering an edge of the pixel electrode. The secondinsulating layer exposes a portion of the pixel electrode and covers atop surface of the metal pattern.

In an exemplary embodiment, the display device further includes anorganic pattern disposed on the second insulating layer in an areacorresponding to the metal pattern. The organic pattern includes a samematerial as the emission layer.

In an exemplary embodiment, the metal pattern and the organic patternare spaced apart from each other, and the second insulating layer isdisposed between the metal pattern and the organic pattern.

In an exemplary embodiment, the display device further includes a secondinsulating layer including a first opening and a second opening. Thefirst opening covers an edge of the pixel electrode and exposes aportion of the pixel electrode, and the second opening covers an edge ofthe metal pattern and exposes a portion of the metal pattern. Theportion of the metal pattern exposed through the second opening contactsthe opposite electrode.

In an exemplary embodiment, the emission layer is disposed on theportion of the pixel electrode exposed through the first opening, and isnot disposed on a remaining portion of the pixel electrode.

In an exemplary embodiment, the display device further includes a groovedisposed in the first insulating layer between the through portion andthe dummy pixel unit.

In an exemplary embodiment, the display device further includes acladding layer disposed on the first insulating layer. The claddinglayer covers the groove and includes a different material than the firstinsulating layer.

In an exemplary embodiment, a depth of the groove is about equal to orless than a thickness of the first insulating layer.

In an exemplary embodiment, the display device further includes a wiringconnection unit disposed between the groove and the dummy pixel unit.

In an exemplary embodiment, the display device further includes a spacedarea disposed between the wiring connection unit and the dummy pixelunit.

In an exemplary embodiment, the display device further includes a metallayer having a ring shape. The metal layer is disposed over the spacedarea and surrounds the through portion, and a diameter of the metallayer is greater than a diameter of the through portion.

In an exemplary embodiment, the substrate includes a display area inwhich the display unit is disposed, and a non-display area disposedadjacent to the display area. The non-display area includes a firstnon-display area surrounding at least a portion of an outer edge of thedisplay area including an edge of the substrate, and a secondnon-display area surrounding at least a portion of an outer edge of thethrough portion between the through portion and the display area.

In an exemplary embodiment, the through portion is disposed adjacent tothe edge of the substrate, and the first non-display area is connectedto the second non-display area.

In an exemplary embodiment, the through portion includes a first throughhole, and a second through hole disposed adjacent to the first throughhole. At least a portion of the dummy pixel unit is disposed between thefirst through hole and the second through hole.

In an exemplary embodiment, the through portion includes a single closedcurve.

In an exemplary embodiment, the groove passes through the firstinsulating layer and extends to at least a portion of the substrate.

According to an exemplary embodiment, a display device includes asubstrate, a first insulating layer disposed on the substrate, a throughportion passing through the substrate and the first insulating layer, asecond insulating layer disposed on the first insulating layer, aplurality of pixels surrounding at least a portion of the throughportion, and a plurality of dummy pixels disposed between the throughportion and the plurality of pixels. Each pixel of the plurality ofpixels includes a light-emitting element including a pixel electrode andan opposite electrode facing each other, and an emission layer disposedbetween the pixel electrode and the opposite electrode. Each dummy pixelof the plurality of dummy pixels includes a metal pattern including asame material as the pixel electrode. The second insulating layerincludes a plurality of openings that exposes every pixel electrode ofthe plurality of pixels, and the second insulating layer completelycovers every metal pattern of the plurality of dummy pixels.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present disclosure will become moreapparent by describing in detail exemplary embodiments thereof withreference to the accompanying drawings, in which:

FIG. 1 is a plan view of a display device according to an exemplaryembodiment.

FIG. 2 is an enlarged plan view of a through portion in a display areaof FIG. 1 according to an exemplary embodiment.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2according to an exemplary embodiment.

FIG. 4 is a cross-sectional view of a display device according to anexemplary embodiment.

FIG. 5 is a cross-sectional view of a display device according to anexemplary embodiment.

FIG. 6 is an enlarged cross-sectional view of portion VI of FIG. 5according to an exemplary embodiment.

FIG. 7 is a cross-sectional view of a display device according to anexemplary embodiment.

FIGS. 8 and 9 are enlarged cross-sectional views of a pixel structure ofFIG. 1 according to an exemplary embodiment.

FIG. 10 is an enlarged plan view of a through portion in a display areaof a display device according to an exemplary embodiment.

FIG. 11 is a cross-sectional view taken along line XI-XI of FIG. 10according to an exemplary embodiment.

FIG. 12 is a plan view of a display device according to an exemplaryembodiment.

FIG. 13 is an enlarged plan view of a through portion in a display areaof FIG. 12 according to an exemplary embodiment.

FIG. 14 is a plan view of a display device according to an exemplaryembodiment.

FIG. 15 is an enlarged plan view of a through portion in a display areaof FIG. 14 according to an exemplary embodiment.

FIGS. 16 and 17 are enlarged cross-sectional views of a display deviceaccording to an exemplary embodiment.

DETAILED DESCRIPTION

Exemplary embodiments of the present disclosure will be described morefully hereinafter with reference to the accompanying drawings. Likereference numerals may refer to like elements throughout theaccompanying drawings.

It will be understood that the terms “first,” “second,” “third,” etc.are used herein to distinguish one element from another, and theelements are not limited by these terms. Thus, a “first” element in anexemplary embodiment may be described as a “second” element in anotherexemplary embodiment.

As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be understood that when a layer, region, or component isreferred to as being “formed on” another layer, region, or component, itcan be directly or indirectly formed on the other layer, region, orcomponent. That is, for example, intervening layers, regions, orcomponents may be present.

When a certain exemplary embodiment may be implemented differently, aspecific process order may be performed differently from the describedorder. For example, two consecutively described processes may beperformed substantially at the same time or performed in an orderopposite to the described order.

Exemplary embodiments may prevent a display device component such as,for example, a wiring that is disposed outside of a display area frombeing viewed due to external light. Exemplary embodiments further allowfor the implementation of a display device that provides differentdisplay area shapes and improves display quality.

It will be understood that when a component, such as a film, a region, alayer, or an element, is referred to as being “on”, “connected to”,“coupled to”, or “adjacent to” another component, it can be directly on,connected, coupled, or adjacent to the other component, or interveningcomponents may be present. It will also be understood that when acomponent is referred to as being “between” two components, it can bethe only component between the two components, or one or moreintervening components may also be present. It will also be understoodthat when a component is referred to as “covering” another component, itcan be the only component covering the other component, or one or moreintervening components may also be covering the other component.

FIG. 1 is a plan view of a display device 1 according to an exemplaryembodiment. FIG. 2 is an enlarged plan view of a through portion TH inthe display area DA of FIG. 1 . FIG. 3 is a cross-sectional view takenalong line III-III of FIG. 2 .

Referring to FIGS. 1 to 3 , the display device 1 includes a substrate100 and a display unit 10 disposed on the substrate 100.

The substrate 100 may include a material such as, for example, glass,metal, or an organic material. According to an exemplary embodiment, thesubstrate 100 may include a flexible material. For example, thesubstrate 100 may include a material that may be warped as desired, andthat is bendable or rollable, such as, for example, polyimide (PI).However, exemplary embodiments of the present disclosure are not limitedthereto.

The substrate 100 includes a display area DA and a non-display area NDA.A through portion TH is disposed in the display area DA. The throughportion TH is a hole that passes through the substrate 100 and variouslayers disposed on the substrate 100, and is disposed inside the displayarea DA and is surrounded by the display unit 10, which includes aplurality of pixels P.

Each pixel P of the display unit 10 includes a pixel circuit and alight-emitting element such as, for example, an organic light-emittingdiode (OLED) electrically connected to the pixel circuit. Each pixel Pprovides a predetermined image through light emitted from thelight-emitting element. The display unit 10 is sealed by anencapsulation layer described below. The encapsulation layer may be, forexample, a multi-layer including a layer including an organic materialand a layer including an inorganic material.

The non-display area NDA is an area that does not provide an image, andincludes a first non-display area NDA1 surrounding an outer edge of thedisplay area DA along an edge of the substrate 100, and a secondnon-display area NDA2 surrounding an outer edge of the through portionTH.

A driving unit DU such as a scan driver and a data driver configured totransfer a preset signal to each pixel P of the display area DA may bedisposed in the first non-display area NDA1. The second non-display areaNDA2 is disposed between the through portion TH and the display area DA.A wiring routing unit to which pixels P adjacent to the secondnon-display area NDA2 are connected may be disposed in the secondnon-display area NDA2.

Although it is shown that the through portion TH is disposed in a rightupper end of the display area DA in the display device 1 of FIG. 1 ,exemplary embodiments of the present disclosure are not limited thereto.For example, according to exemplary embodiments, the through portion THmay be disposed anywhere in the display area DA.

Also, although it is shown that the through portion TH is circular andthat one through portion TH is provided in the display device of FIG. 1, exemplary embodiments of the present disclosure are not limitedthereto. For example, according to exemplary embodiments, the throughportion TH may have various shapes such as a polygon or an ellipticalshape, and one or more through portions TH may be provided (see, e.g.,FIGS. 12 and 13 ).

Also, although it is shown that the display area DA is a quadrangle inthe display device of FIG. 1 , exemplary embodiments of the presentdisclosure are not limited thereto. For example, the display area DA maybe a polygon instead of a quadrangle, or may have various shapes such asa circular shape and an elliptical shape.

Referring to FIGS. 2 and 3 , the through portion TH is disposed insidethe display unit 10. As a result, the through portion TH is surroundedby pixels P. A region in which a pixel P is not provided, that is, thesecond non-display area NDA2, is disposed between the through portion THand the pixels P.

The through portion TH passes through the substrate 100, anencapsulation layer 400, and layers disposed therebetween. The throughportion TH may be formed by cutting/punching equipment using a laser,etc. A crack may occur in the vicinity of the through portion TH due toan impact during a process of forming the through portion TH by usingthe cutting equipment. Thus, in an exemplary embodiment, a crackprevention pattern 300A is disposed in the second non-display area NDA2.The crack prevention pattern 300A may prevent the crack from propagatingtoward a pixel P.

The crack prevention pattern 300A includes a groove 310A and a claddinglayer 320A covering the groove 310A. The groove 310A has a ring shapehaving a radius greater than a radius of the through portion TH, andsurrounds an outer edge of the through portion TH, as illustrated inFIG. 2 . Although it is shown that the through portion TH is circularand the groove 310A has a circular ring shape, exemplary embodiments ofthe present disclosure are not limited thereto. For example, in anexemplary embodiment, the groove 310A may have a polygonal ring shapesuch as a triangular ring shape and a quadrangular ring shape, or anelliptical ring shape.

The groove 310A is a recess that is concave in a thickness direction ofa first insulating layer 110 disposed on the substrate 100, and mayblock a crack from propagating toward the display area DA. For example,the groove 310A may be formed in the first insulating layer 110 and maybe concave in a direction toward the substrate 100. The groove 310A mayhave a depth dl that is about equal to or less than a thickness t of thefirst insulating layer 110. In an exemplary embodiment, the depth dl mayrange from about 6000 Å to about 8000 Å.

The first insulating layer 110 including the groove 310A is an inorganiclayer, and may be a single inorganic layer including the firstinsulating layer 110 or a plurality of inorganic layers including aplurality of layers. For example, the first insulating layer 110 mayinclude an inorganic material such as silicon oxide, silicon nitride,and silicon oxynitride.

The cladding layer 320A overlaps the groove 310A and covers the groove310A. The cladding layer 320A may be disposed directly on the firstinsulating layer 110 such that the cladding layer 320A directly contactsthe groove 310A. A portion of the cladding layer 320A may be disposedinside the groove 310A.

The cladding layer 320A may include an organic insulating material. Forexample, the cladding layer 320A may include the same material as a vialayer 130 and/or a second insulating layer 150.

A top surface of the cladding layer 320A may be relatively flat, and thecladding layer 320A may cover the groove 310A. In an exemplaryembodiment, a total thickness of the cladding layer 320A (e.g., athickness from a bottom surface to a top surface of the cladding layer320A filling the groove 310A) may range from about 7000 Å to about150000 Å. However, exemplary embodiments of the present disclosure arenot limited thereto.

The cladding layer 320A may reduce stress of a portion of the firstinsulating layer 110, which is an inorganic layer, in which the groove310A has been formed, and may prevent a crack from propagating. Also,the cladding layer 320A covers the groove 310A and may prevent particlesfrom collecting in the groove 310A during a manufacturing process andmoving to a light-emitting element 500 of a pixel P, which may generatea black spot.

A dummy pixel unit 20 is disposed in the second non-display area NDA2.The dummy pixel unit 20 may be disposed between the display area DA andthe crack prevention pattern 300A and includes dummy pixels DP. Thedummy pixel unit 20 may be disposed in a portion of the secondnon-display area NDA2 adjacent to the display area DA. An area in whichthe dummy pixel unit 20 is disposed may be defined as a dummy pixel areaDMA.

As illustrated in FIG. 3 , the dummy pixel unit 20 is an area extendingfrom the display unit 10 and provided as one body with the display unit10. The dummy pixel unit 20 is a unit in which a pixel is disposed, butin which the pixel does not actually emit light and is disposed as adummy. Therefore, dummy pixels DP of the dummy pixel unit 20 aredisposed successive with the pixels P of the display unit 10. Forexample, in an exemplary embodiment, the dummy pixels DP of the dummypixel unit 20 and the pixels P of the display unit 10 are aligned withone another.

In an exemplary embodiment, about one to three pixels may be provided asdummy pixels DP. However, exemplary embodiments of the presentdisclosure are not limited thereto. For example, the number of dummypixels DP may be varied by taking different factors into account suchas, for example, a size of the through portion TH, a shape of thethrough portion TH, a width of a dead space, etc.

As a comparative example, if pixels P that normally emit light (e.g.,not dummy pixels DP) are disposed in the dummy pixel unit 20, when thethrough portion TH is formed by cutting/punching equipment using alaser, etc., some of the pixels P disposed in the vicinity of thethrough portion TH may be damaged. Also, a characteristic of a pixelcircuit is changed by an arrangement change of the pixels P neighboringthe through portion TH due to the through portion TH, which causes aparasitic capacitance difference between the pixels P neighboring thethrough portion TH and the pixels P that do not neighbor the throughportion. As a result, in the comparative example, a stain of the pixelsP neighboring the through portion TH may be generated, and reliabilityof the display unit may be reduced.

A wiring connection unit 330 is disposed between the crack preventionpattern 300A and the dummy pixel unit 20 in the display unit 10. Thewiring connection unit 330 includes wirings configured to supply asignal to the pixels P disposed in the vicinity of the through portionTH, may be a scan signal wiring or a data signal wiring, and is designedto bypass the through portion TH.

Since the through portion TH is disposed inside the display area DA,design of the pixels P neighboring the through portion TH and thewirings configured to supply a signal to the pixels P is changed, whichcauses a deviation in a parasitic capacitance between the pixels P, andconsequently causes a stain of the pixels P neighboring the throughportion TH.

Therefore, the display device 1 according to an exemplary embodiment mayremove a stain defect of the pixels neighboring the through portion TH,and may improve the quality of the display unit 10 by configuring thepixels P disposed in the vicinity of the through portion TH by using thedummy pixels DP that do not emit light.

Referring to the display area DA of FIG. 3 , a pixel circuit 200 and alight-emitting element 500 are disposed in the display area DA.

The light-emitting element 500 includes a pixel electrode 510electrically connected to the pixel circuit 200 with the via layer 130including a contact hole CH disposed therebetween, an opposite electrode530 facing the pixel electrode 510, and an emission layer 520 disposedtherebetween. In an exemplary embodiment, the via layer 130 may includean insulating organic material.

The pixel electrode 510 is exposed through an opening OP provided in thesecond insulating layer 150, and an edge of the pixel electrode 510 maybe covered by the second insulating layer 150 including an insulatingorganic material. In an exemplary embodiment, the pixel electrode 510may include, for example, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Jr, Cr, or acompound thereof. The second insulating layer 150 is a pixel-defininglayer. In an exemplary embodiment, the second insulating layer 150covers an edge of the pixel electrode 510, and exposes a central portionof the pixel electrode 510.

The opposite electrode 530 may be provided as one body and maycompletely cover the display area DA. In an exemplary embodiment, theopposite electrode 530 may be, for example, a thin film metal layerincluding Ag and Mg, or a transparent conductive oxide (TCO) such asindium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO),indium oxide (In₂O₃), indium gallium oxide (IGO), or aluminum zinc oxide(AZO).

In an exemplary embodiment, an end 530E of the opposite electrode 530may cover an end 130E of the via layer 130 and may be disposed betweenthe via layer 130 and the wiring connection unit 330, as illustrated inFIG. 3 . In an exemplary embodiment, the end 530E of the oppositeelectrode 530 may extend to an edge 100E of the substrate 100 in whichthe through portion TH has been formed, as illustrated in FIG. 4 . Astructure of the opposite electrode 530 shown in FIG. 4 is applicable toother exemplary embodiments described herein.

The emission layer 520 may include an organic material including afluorescence or phosphorescence material that emits red, green, or bluelight, and may be patterned to correspond to the pixels P of the displayarea DA. At least one of a first functional layer 522 disposed betweenthe emission layer 520 and the pixel electrode 510, and a secondfunctional layer 524 disposed between the emission layer 520 and theopposite electrode 530, may be provided. Unlike the emission layer 520patterned over the pixel electrode 510, the first functional layer 522and the second functional layer 524 may be common layers provided on theentire surface of the display unit 10.

The first functional layer 522 may include at least one of, for example,a hole injection layer (HIL) and a hole transport layer (HTL). The HILallows holes to be emitted from an anode, and the HTL allows holes ofthe HIL to be transferred to the emission layer 520.

The HIL may include a phthalocyanine compound such as, for example,copper phthalocyanine, DNTPD(N,N′-diphenyl-N,N′-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4′-diamine,m-MTDATA(4,4′,4 “-tris(3-methylphenylphenylamino) triphenylamine,TDATA(4,4′4”-Tris(N,N-diphenylamino)triphenylamine,2T-NATA(4,4′,4″-tris{N,-(2-naphthyl)-N-phenylamino}-triphenylamine,PEDOT/PSS (Poly(3,4-ethylenedioxythiophene)/Poly(4-styrenesulfonate),Pani/DBSA(Polyaniline/Dodecylbenzenesulfonic acid), Pani/CSA(Polyaniline/Camphor sulfonicacid), or PANI/PSS(Polyaniline)/Poly(4-styrenesulfonate), and is not limited thereto.

The HTL may include carbazole derivatives such as, for example, N-phenylcarbazole, polyvinyl carbazole, etc.,TPD(N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine,NPB(N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine, and atriphenylamine-based material such as, for example,TCTA(4,4′,4″-tris(N-carbazolyl)triphenylamine, and is not limitedthereto.

The second functional layer 524 may include at least one of an electrontransport layer (ETL) and an electron injection layer (EIL). The EILallows electrons to be emitted from a cathode, and the ETL allowselectrons of the EIL to be transferred to the emission layer 520.

The ETL may include, for example, Alq3,BCP(2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline),Bphen(4,7-Diphenyl-1,10-phenanthroline),TAZ(3-(4-Biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole),NTAZ(4-(Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole),4tBu-PBD(2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole),BAlq(Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1′-Biphenyl-4-olato)aluminum),Bebq2 (beryllium bis(benzoquinolin-10-olate)),ADN(9,10-di(naphthalene-2-yl)anthracene, and is not limited thereto.

The EIL may include a material such as, for example, LiF, NaCl, CsF,Li₂O, BaO, and Liq, and is not limited thereto.

In an exemplary embodiment, unlike the actual pixel P, an opening OP isnot formed in the second insulating layer 150 with respect to the dummypixel DP.

As described above, in the pixel P of the display unit 10, a centralportion of the pixel electrode 510 is exposed through the opening OP ofthe second insulating layer 150, and the emission layer 520 is disposedon the pixel electrode 510 such that the emission layer 520 is disposedbetween the pixel electrode 510 and the opposite electrode 530.

In contrast, a dummy pixel DP includes a metal pattern 510Dcorresponding to the pixel electrode 510 of the pixel P, and the secondinsulating layer 150 completely covers the metal pattern 510D and doesnot include the opening OP, unlike the actual pixel P. Therefore, in thedummy pixel DP, the second insulating layer 150 is entirely disposedbetween the metal pattern 510D and an organic pattern 520D correspondingto the emission layer 520 of the pixel P. Therefore, since the organicpattern 520D of the dummy pixel DP does not directly contact the metalpattern 510D of the dummy pixel DP, the dummy pixel DP does not actuallyemit light. Rather, when driven, the dummy pixel DP is expressed as ablack dead space like the second non-display area NDA2.

Thus, in an exemplary embodiment, the second insulating layer 150includes a plurality of openings OP that exposes every pixel electrode510 of the plurality of pixels P, and the second insulating layer 150does not include any openings in areas corresponding to the dummy pixelsDP, and thus, the second insulating layer 150 completely covers everymetal pattern 510D of the plurality of dummy pixels DP.

The encapsulation layer 400 is disposed on the pixels P and the dummypixels DP. However, exemplary embodiments of the present disclosure arenot limited thereto. For example, in an exemplary embodiment, instead ofthe encapsulation layer 400, the display unit 10 is sealed by providingan encapsulation substrate over the substrate 100 and bonding thesubstrate 100 onto the encapsulation substrate by using a sealant on anouter periphery of the substrate 100. A structure of sealing the displayunit 10 by using the encapsulation layer 400 is described herein.

The encapsulation layer 400 includes inorganic encapsulation layers 410and 430 and an organic encapsulation layer 420. For example, theencapsulation layer 400 may include the inorganic encapsulation layer410, the organic encapsulation layer 420, and the inorganicencapsulation layer 430 sequentially stacked on one another. Theinorganic encapsulation layers 410 and 430 may include at least one of,for example, silicon nitride, aluminum nitride, zirconium nitride,titanium nitride, hafnium nitride, tantalum nitride, silicon oxide,aluminum oxide, titanium oxide, tin oxide, cesium oxide, and siliconoxynitride. The inorganic encapsulation layers 410 and 430 may be formedby chemical vapor deposition (CVD).

The organic encapsulation layer 420 may include at least one of, forexample, an acrylic-based resin, a methacrylate-based resin, apolyisoprene vinyl-based resin, an epoxy resin, a urethane-based resin,a cellulose resin, and a perylene-based resin.

In an exemplary embodiment, the organic encapsulation layer 420 may beformed by an atomic layer deposition (ALD) process that uses a materialsuch as, for example, hexamethyldisiloxane (HMDSO) or tetradthlyorthosilicate (TEOS) as a material gas.

In an exemplary embodiment, the organic encapsulation layer 420 may beformed by depositing a liquid monomer and then hardening the same usingheat or light such as an ultraviolet ray. To prevent the liquid monomerfrom flowing toward the crack prevention pattern 300A and an edge tailof the organic encapsulation layer 420 from being formed, a dam may bedisposed in the second non-display area NDA2. An end of the organicencapsulation layer 420 may be disposed between the dam and the pixel Pby the dam.

Although the encapsulation layer 400 in the exemplary embodimentdescribed herein includes the two inorganic encapsulation layers 410 and430 and the one organic encapsulation layer 420, a stacking sequence andthe numbers of inorganic encapsulation layers and organic encapsulationlayers are not limited thereto.

FIGS. 5 to 7 are cross-sectional views of a display device according toan exemplary embodiment.

An exemplary embodiment of FIGS. 5 and 7 is different from the exemplaryembodiment of FIG. 3 with relation to a structure of the dummy pixel DPof the dummy pixel unit 20. For convenience of explanation, thedifference with relation to the structure of the dummy pixel DP isprimarily described, and a further description of components previouslydescribed may be omitted.

Unlike FIG. 3 , in the dummy pixel DP of FIG. 5 , the organic pattern520D (the emission layer) is not disposed.

In the pixel P of the display unit 10, the second insulating layer 150includes a first opening OP1 that covers an edge of the pixel electrode510 and exposes a central portion of the pixel electrode 510, theemission layer 520 is disposed on the pixel electrode 510, and theopposite electrode 530 is disposed on the emission layer 520. In anexemplary embodiment, the emission layer 520 is disposed on the portionof the pixel electrode 510 exposed through the first opening OP1 (e.g.,the exposed central portion of the pixel electrode 510), and is notdisposed on a remaining portion of the pixel electrode 510. That is, inan exemplary embodiment, the only portion of the pixel electrode 510that the emission layer 520 is disposed on is the portion of the pixelelectrode 510 exposed through the first opening OP1 (e.g., the exposedcentral portion of the pixel electrode 510).

Similarly, in the dummy pixel DP of the dummy pixel unit 20, the secondinsulating layer 150 includes a second opening OP2 that covers an edgeof the metal pattern 510D and exposes a central portion of the metalpattern 510D. However, in this case, the organic pattern 520Dcorresponding to the emission layer 520 is not disposed on the metalpattern 510D. Therefore, as shown in FIG. 6 , which is an enlargedcross-sectional view of portion VI in FIG. 5 , the opposite electrode530 may directly contact a top surface of the metal pattern 510D.

Referring to FIG. 6 , an opening OP3 that exposes the top surface of themetal pattern 510D may be formed in the first and second functionallayers 522 and 524. The organic pattern may be formed on the metalpattern 510D during a manufacturing process and simultaneously removedduring a process of forming the opening OP3. At least a portion of theopposite electrode 530 may directly contact the top surface of the metalpattern 510D through the opening OP3 formed in the first and secondfunctional layers 522 and 524.

Referring to FIG. 7 , in an exemplary embodiment, a structure of thedummy pixel DP may be formed to be the same as that of the pixel P. Inthis case, the light-emitting element 500 of the pixel P includes thepixel electrode 510, the emission layer 520, and the opposite electrode530. Similarly, the dummy pixel DP includes the metal pattern 510D, theorganic pattern 520D, and the opposite electrode 530.

However, in the exemplary embodiment of FIG. 7 , the dummy pixel DP isnot electrically connected to a second pixel circuit 200D disposedtherebelow. The second pixel circuit 200D may be the same circuitelement as the first pixel circuit 200 disposed in the display unit 10.

In the pixel P of the display unit 10, the pixel electrode 510 iselectrically connected to the first pixel circuit 200 disposedtherebelow through a contact hole CH formed in the via layer 130. Thepixel electrode 510 being electrically connected to the first pixelcircuit 200 may mean that the pixel electrode 510 is electricallyconnected to a source electrode or a drain electrode of a thin filmtransistor of the first pixel circuit 200.

In the dummy pixel DP of the dummy pixel unit 20, the second pixelcircuit 200D is disposed below the metal pattern 510D, but the metalpattern 510D is electrically insulated from the second pixel circuit200D. For example, in an exemplary embodiment, the contact hole CH isnot disposed between the second pixel circuit 200D and the metal pattern510D, and as a result, the metal pattern 510D is not connected to thesecond pixel circuit 200D.

That is, in an exemplary embodiment, a contact hole is not formed in aportion of the via layer 130 on which the metal pattern 510D isdisposed, and therefore, the dummy pixel DP is not electricallyconnected to the second pixel circuit 200D. In an exemplary embodiment,the pixel circuit 200 is not disposed below the dummy pixel DP.

FIGS. 8 and 9 are enlarged cross-sectional views of a pixel structure ofFIG. 1 according to an exemplary embodiment.

FIGS. 8 and 9 are cross-sectional views of a portion of the pixel P inthe display area DA of a display device according to an exemplaryembodiment. For convenience of explanation, since the display device ofFIGS. 8 and 9 includes the same configuration as that of the displaydevice described with reference to FIG. 3 , the pixel circuit 200 isprimarily described below, and a further description of componentspreviously described may be omitted.

Referring to FIG. 8 , in an exemplary embodiment, the pixel circuit 200includes a thin film transistor 210 and a storage capacitor 220. Thefirst insulating layer 110 may include a buffer layer 101, a gateinsulating layer 103, a dielectric insulating layer 105, and aninterlayer insulating layer 107 sequentially disposed on the substrate100.

The buffer layer 101 may prevent penetration of impurities. The gateinsulating layer 103 is disposed between a semiconductor layer 211 and agate electrode 213 of the thin film transistor 210. The dielectricinsulating layer 105 is disposed between a bottom electrode 221 and atop electrode 223 of the storage capacitor 220. The interlayerinsulating layer 107 is disposed between the gate electrode 213, asource electrode 215 s, and a drain electrode 215 d of the thin filmtransistor 210.

All of the buffer layer 101, the gate insulating layer 103, thedielectric insulating layer 105, and the interlayer insulating layer 107may include an insulating inorganic material. For example, each of thebuffer layer 101, the gate insulating layer 103, the dielectricinsulating layer 105, and the interlayer insulating layer 107 mayinclude silicon nitride, silicon oxide, and/or silicon oxynitride.

Although the exemplary embodiment of FIG. 8 illustrates that the thinfilm transistor 210 overlaps the storage capacitor 220, and thus, thegate electrode 213 of the thin film transistor 210 serves as the bottomelectrode 221 of the storage capacitor 220, exemplary embodiments of thepresent disclosure are not limited thereto.

Referring to FIG. 9 , the thin film transistor 210 and the storagecapacitor 220 of the pixel circuit 200 may be disposed at differentlocations.

Depending on a structure of the pixel circuit 200, the first insulatinglayer 110 may include the buffer layer 101, the gate insulating layer103, and the interlayer insulating layer 107 sequentially disposed onthe substrate 100. As illustrated in FIG. 9 , the interlayer insulatinglayer 107 may be disposed between the bottom electrode 221 and the topelectrode 223 of the storage capacitor 220 to perform a function of adielectric.

Although it has been described that the thin film transistor 210 of thepixel circuit 200 is a top-gate type transistor in FIGS. 8 and 9 ,exemplary embodiments are not limited thereto. For example, in anexemplary embodiment, the thin film transistor 210 may be a bottom-gatetype transistor. Also, although a case has been described in which thebottom electrode 221 and the top electrode 223 of the storage capacitor220 are disposed on the same layers and respectively include the samematerials as the gate electrode 213, and the source electrode 215 s andthe drain electrode 215 d in FIG. 8 , exemplary embodiments are notlimited thereto and may be modified variously.

FIG. 10 is an enlarged plan view of a through portion in a display areaof a display device according to an exemplary embodiment. FIG. 11 is across-sectional view taken along line XI-XI of FIG. 10 according to anexemplary embodiment.

An exemplary embodiment of FIGS. 10 and 11 further includes a metallayer 600 disposed between the wiring connection unit 330 and the dummypixel unit 20. The metal layer 600 may be disposed over a spaced area SAbetween the wiring connection unit 330 and the dummy pixel unit 20.

The metal layer 600 may surround areas that surround the through portionTH, and may have a ring shape that has a greater diameter than thethrough portion TH, as shown in FIG. 10 . However, the shape of themetal layer 600 is not limited thereto, and may be modified depending onthe shape of the through portion TH and may be designed separately fromthe shape of the through portion TH.

Referring to FIG. 11 , in an exemplary embodiment the metal layer 600may include the same material as that of the pixel electrode 510. In anexemplary embodiment, the metal layer 600 may include the same materialas that of other conductive layers included in the pixel circuit 200.For example, in the structure of the pixel circuit 200, the metal layer600 may include the same material as that of the gate electrode 213 ofthe thin film transistor 210 or the top electrode 223 of the storagecapacitor 220, and may include the same material as that of the sourceelectrode 215 s and the drain electrode 215 d of the thin filmtransistor 210. For example, in the structure of the pixel circuit 200of FIG. 8 , the metal layer 600 may include the same material as that ofthe gate electrode 213, or the source electrode 215 s and the drainelectrode 215 d of the thin film transistor 210.

The metal layer 600 may physically separate the wiring connection unit330 from adjacent pixels P and may simultaneously prevent coupling.

In a display device according to an exemplary embodiment, a dummy pixelarea DMA is implemented in an approximately circular shape and surroundsthe neighboring area of the through portion TH. However, exemplaryembodiments are not limited thereto. For example, according to exemplaryembodiments, the dummy pixel area DMA may be implemented in variousshapes such as an elliptical shape, a straight line shape, and aU-shape.

FIG. 12 is a plan view of a display device 2 according to an exemplaryembodiment. FIG. 13 is an enlarged plan view of the through portion THin the display area DA of FIG. 12 according to an exemplary embodiment.

FIGS. 12 and 13 are different from the above-described exemplaryembodiments in terms of the through portion TH and a shape of the secondnon-display area NDA2 in the neighboring area of the through portion TH.For convenience of explanation, since the configuration otherwise issimilar to that of the above-described exemplary embodiments, thethrough portion TH and the second non-display area NDA2 are primarilydescribed below, and a further description of components previouslydescribed may be omitted.

Referring to FIG. 12 , in an exemplary embodiment, the display device 2may include two or more through portions, for example, first and secondthrough portions TH1 and TH2, disposed inside the display area DA. Thethrough portion TH may include the first through portion TH1 and thesecond through portion TH2. The second non-display area NDA2 is disposedaround the through portion TH such that it surrounds the through portionTH.

Referring to FIG. 13 , in an exemplary embodiment, the through portionTH is disposed inside the display area DA. The through portion THincludes the first through portion TH1 and the second through portionTH2. Although the through portion TH includes the two through portionsTH1 and TH2 in the exemplary embodiment described herein, exemplaryembodiments are not limited thereto.

Similar to the above-described exemplary embodiments, the crackprevention pattern 300A may be disposed around the through portion THsuch that it surrounds the first through portion TH1 and the secondthrough portion TH2. The wiring connection unit 330 may be disposedoutside of the crack prevention pattern 300A.

The dummy pixel unit 20 including the dummy pixels DP is disposed aroundthe through portion TH. At least one of the exemplary embodiments ofFIGS. 3 to 6 is applicable referring to the structures of the dummypixels DP. The dummy pixel unit 20 is disposed between the wiringconnection unit 330 and the display unit 10.

The dummy pixels DP may be disposed in the second non-display area NDA2disposed around the through portion TH. The dummy pixels DP surroundareas surrounding the first through portion TH1 and the second throughportion TH2. For example, in an exemplary embodiment, the dummy pixelsDP may also be disposed in a region between the first through portionTH1 and the second through portion TH2. Since the dummy pixels DP arerecognized as a dead space that does not emit light, visibility may beimplemented as if the first through portion TH1 were connected to thesecond through portion TH2 by arranging the dummy pixels DP in theregion between the first through portion TH1 and the second throughportion TH2.

As described above, the through portion TH may be implemented in variousshapes as well as a circular shape. To form the through portion THitself in an elliptical shape (or a bar shape) as shown in FIG. 13 , thesubstrate and structures on the substrate are exposed to a laser for arelatively longer time, which may cause defects in elements neighboringthe through portion TH.

Therefore, the shapes of the through portion TH and the secondnon-display area NDA2 that are viewable from the outside (e.g., viewableby a user using the display device 2) may be variously implemented bydesigning the through portion TH itself in a shape formable for aminimum or reduced duration, and by arranging the dummy pixels DP aroundthe through portion TH.

FIG. 14 is a plan view of a display device 3 according to an exemplaryembodiment. FIG. 15 is an enlarged plan view of a through portion TH ina display area DA and a non-display area NDA of FIG. 14 according to anexemplary embodiment.

Exemplary embodiments of FIGS. 14 and 15 are different from theabove-described exemplary embodiments in terms of a location of thethrough portion TH and a shape of the non-display area NDA around thethrough portion TH. For convenience of explanation, since theconfiguration otherwise is similar to that of the above-describedexemplary embodiments, the through portion TH and the non-display areaNDA are primarily described below, and a further description ofcomponents previously described may be omitted.

Referring to FIG. 14 , in an exemplary embodiment, the display device 3includes a first non-display area NDA1 surrounding at least a portion ofan outer edge of the display area DA, and a second non-display area NDA2surrounding at least a portion of an outer edge of the through portionTH between the through portion TH and the display area DA. The throughportion TH is disposed in an upper central portion of the display areaDA and is disposed adjacent to an edge of the substrate 100. In theabove-described exemplary embodiments, the second non-display area NDA2is surrounded by the display area DA. In contrast, in the exemplaryembodiment described herein, the display area DA surrounds a portion ofthe second non-display area NDA2, and the rest of the second non-displayarea NDA2 is connected to the first non-display area NDA1.

In a case in which the display unit 10 emits light, the display area DAof the display device 3 in FIG. 14 may be recognized as if a U-shapedrecess U were formed in a portion in which the through portion TH isdisposed.

Referring to FIG. 15 , although the crack prevention pattern 300Asurrounding the through portion TH and the wiring connection unit 330are substantially spaced apart from the first non-display area NDA1, itmay be recognized as if the first non-display area NDA1 were visuallyconnected with the second non-display area NDA2 through the dummy pixelunit 20 disposed between the first non-display area NDA1 and the wiringconnection unit 330.

As described above, deterioration of an emission uniformity of pixels Pneighboring the through portion TH may be prevented or reduced, and avisually displayed shape of the non-display area NDA may be freelyimplemented by designing a location and an area of the dummy pixel unit20 as described herein according to exemplary embodiments.

FIGS. 16 and 17 illustrate an exemplary embodiment of a crack preventionpattern 300A′. Referring to FIGS. 16 and 17 , in an exemplaryembodiment, the crack prevention pattern 300A′ includes a first groove310A1 and a second groove 310A2. The first and second grooves 310A1 and310A2 may completely pass through the first insulating layer 110 and mayextend to at least a portion of the substrate 100. For example, a deptht2 of the first and second grooves 310A1 and 310A2 may be greater than athickness t1 of the first insulating layer 110.

Undercut-shaped step difference portions UC1 and UC2 may be formed atends of the first and second grooves 310A1 and 310A2. Each of the firstand second grooves 310A1 and 310A2 has a structure having a graduallyreducing width toward the substrate 100 while extending in a directionof the substrate 100. The width of the first and second grooves 310A1and 310A2 is relatively widened at the step difference portions UC1 andUC2. The opposite electrode 530 is disconnected as described below bythe undercut shape of the step difference portions UC1 and UC2. Sincethe opposite electrode 530 is disconnected, a lateral moisturetransmission path through an interface between the opposite electrode530 and layers disposed adjacent thereto may be blocked.

The opposite electrode 530 and the inorganic encapsulation layers 410and 430 may be disposed over the first and second grooves 310A1 and310A2. The opposite electrode 530 and the inorganic encapsulation layers410 and 430 may be disposed entirely over the substrate 100 and mayextend to the edge 100E of the substrate 100. As described above, theopposite electrode 530 may be disconnected by the undercut shape of thestep difference portions UC1 and UC2, and in this case, a portion 530Aof the opposite electrode 530 may be disposed inside the first andsecond grooves 310A1 and 310A2.

The first groove 310A1 of the crack prevention pattern 300A′ is disposedrelatively adjacent to the through portion TH compared to the secondgroove 310A2. For example, the first groove 310A1 is disposed closer tothe through portion TH compared to the second groove 310A2, and thesecond groove 310A2 is disposed closer to the display area DA comparedto the first groove 310A1. The inside of the second groove 310A2 may befilled with an organic material 420A. The organic material 420A may bethe same material as that of the organic encapsulation layer 420 of theencapsulation layer 400. In the second groove 310A2, the inorganicencapsulation layer 410 covers an inner surface of the second groove310A2, the organic material 420A fills the inside of the second groove310A2, and the inorganic encapsulation layer 430 covers the organicmaterial 420A.

FIGS. 16 and 17 illustrate a stacked structure including the crackprevention pattern 300A′ in more detail.

The substrate 100 of FIG. 17 may include a multi-layered structure of anorganic/inorganic composite layer. For example, the substrate 100includes first and second substrate layers 100 a 1 and 100 a 2 having adouble-layered structure, and first and second barrier layers 100 b 1and 100 b 2 are disposed alternately with the first and second substratelayers 100 a 1 and 100 a 2 disposed therebetween.

Similar to FIG. 8 , the first insulating layer 110 including the bufferlayer 101, the gate insulating layer 103, the dielectric insulatinglayer 105, and the interlayer insulating layer 107, the via layer 130,and the second insulating layer 150 are sequentially disposed on thesubstrate 100. A portion of the via layer 130 and the second insulatinglayer 150 corresponding to a groove area GA is removed. The crackprevention pattern 300A′ including the first and second grooves 310A1and 310A2 is disposed in the groove area GA.

The crack prevention pattern 300A′ includes the first groove 310A1disposed adjacent to the through portion TH, and the second groove 310A2disposed outside the first groove 310A1. The first and second grooves310A1 and 310A2 extend to the second substrate layer 100 a 2, and theundercut-shaped step difference portions UC1 and UC2 are formed betweenthe second substrate layer 100 a 2 and the second barrier layer 100 b 2.

As illustrated in FIG. 17 , the first and second grooves 310A1 and 310A2may have step difference portions ST1 and ST2 between the buffer layer101 and the gate insulating layer 103, and between the interlayerinsulating layer 107 and the via layer 130.

While the present disclosure has been particularly shown and describedwith reference to the exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and detail may be made therein without departing from the spiritand scope of the present disclosure as defined by the following claims.

What is claimed is:
 1. A display device, comprising: a substrate havinga non-display portion, a display area surrounding at least a portion ofthe non-display portion and a non-display area disposed adjacent to thedisplay area; a display unit disposed on the first insulating layer inthe display area and comprising a plurality of pixels surrounding of thenon-display portion, wherein each pixel comprises a light-emittingelement comprising a pixel electrode and an opposite electrode facingeach other, and an emission layer disposed between the pixel electrodeand the opposite electrode; and a dummy pixel unit comprising aplurality of dummy pixels disposed between the non-display portion andthe display unit, and comprising a metal pattern comprising a samematerial as the pixel electrode, wherein the dummy pixels are disposedadjacent to the display unit.
 2. The display device of claim 1, whereinthe dummy pixels of the dummy pixel unit are disposed successive withthe pixels of the display unit.
 3. The display device of claim 1,further comprising: a first pixel circuit; and a second pixel circuit,wherein each of the first pixel circuit and the second pixel circuitcomprises a thin film transistor disposed on the substrate, wherein afirst pixel from among the plurality of pixels is electrically connectedto the first pixel circuit, and a first dummy pixel from among theplurality of dummy pixels is electrically insulated from the secondpixel circuit.
 4. The display device of claim 3, further comprising: avia layer covering the first pixel circuit and the second pixel circuit,wherein the via layer planarizes a top surface of the via layer, andcomprises a contact hole that electrically connects the first pixel tothe first pixel circuit, wherein the contact hole is not disposedbetween the second pixel circuit and the metal pattern.
 5. The displaydevice of claim 3, wherein the pixel electrode is electrically connectedto the thin film transistor of the first pixel circuit, and the metalpattern is electrically insulated from the thin film transistor of thesecond pixel circuit.
 6. The display device of claim 1, furthercomprising: a second insulating layer covering an edge of the pixelelectrode, wherein the second insulating layer exposes a portion of thepixel electrode and covers a top surface of the metal pattern.
 7. Thedisplay device of claim 6, further comprising: an organic patterndisposed on the second insulating layer in an area corresponding to themetal pattern, wherein the organic pattern comprises a same material asthe emission layer.
 8. The display device of claim 7, wherein the metalpattern and the organic pattern are spaced apart from each other, andthe second insulating layer is disposed between the metal pattern andthe organic pattern.
 9. The display device of claim 1, furthercomprising: a second insulating layer comprising a first opening and asecond opening, wherein the first opening covers an edge of the pixelelectrode and exposes a portion of the pixel electrode, and the secondopening covers an edge of the metal pattern and exposes a portion of themetal pattern, wherein the portion of the metal pattern exposed throughthe second opening contacts the opposite electrode.
 10. The displaydevice of claim 9, wherein the emission layer is disposed on the portionof the pixel electrode exposed through the first opening, and is notdisposed on a remaining portion of the pixel electrode.
 11. The displaydevice of claim 1, further comprising: a first insulating layer disposedon the substrate; a groove disposed in the first insulating layerbetween the non-display portion and the dummy pixel unit.
 12. Thedisplay device of claim 11, further comprising: a cladding layerdisposed on the first insulating layer, wherein the cladding layercovers the groove and comprises a different material than the firstinsulating layer.
 13. The display device of claim 11, wherein a depth ofthe groove is about equal to or less than a thickness of the firstinsulating layer.
 14. The display device of claim 11, furthercomprising: a wiring connection unit disposed between the groove and thedummy pixel unit.
 15. The display device of claim 14, furthercomprising: a spaced area disposed between the wiring connection unitand the dummy pixel unit.
 16. The display device of claim 15, furthercomprising: a metal layer having a ring shape, wherein the metal layeris disposed over the spaced area and surrounds the non-display portion,and a diameter of the metal layer is greater than a diameter of thenon-display portion.
 17. The display device of claim 1, wherein thenon-display area comprises a first non-display area surrounding at leasta portion of an outer edge of the display area comprising an edge of thesubstrate, and a second non-display area surrounding at least a portionof an outer edge of the non-display portion between the non-displayportion and the display area.
 18. The display device of claim 17,wherein the non-display portion is disposed adjacent to the edge of thesubstrate, and the first non-display area is connected to the secondnon-display area.
 19. The display device of claim 1, wherein thenon-display portion comprises: a first through hole; and a secondthrough hole disposed adjacent to the first through hole, wherein atleast a portion of the dummy pixel unit is disposed between the firstthrough hole and the second through hole.
 20. The display device ofclaim 1, wherein an edge of the non-display portion comprises a singleclosed curve.
 21. The display device of claim 11, wherein the groovepasses through the first insulating layer and extends to at least aportion of the substrate.
 22. A display device, comprising: a substrate;a non-display portion defined in the substrate a first insulating layerdisposed on the substrate; a second insulating layer disposed on thefirst insulating layer; a plurality of pixels surrounding at least aportion of the non-display portion, wherein each pixel comprises alight-emitting element comprising a pixel electrode and an oppositeelectrode facing each other, and an emission layer disposed between thepixel electrode and the opposite electrode; and a plurality of dummypixels disposed between the non-display portion and the pixels, whereineach dummy pixel comprises a metal pattern comprising a same material asthe pixel electrode, wherein the second insulating layer comprises aplurality of openings that exposes every pixel electrode of theplurality of pixels, and the second insulating layer completely coversevery metal pattern of the plurality of dummy pixels.